Field of the Invention
The present invention relates generally to the field of corn breeding. In particular, the invention relates to corn seed and plants of the hybrid variety designated CH702044, and derivatives and tissue cultures thereof.
Description of Related Art
The goal of field crop breeding is to combine various desirable traits in a single variety/hybrid. Such desirable traits include greater yield, better stalks, better roots, resistance to insecticides, herbicides, pests, and disease, tolerance to heat and drought, reduced time to crop maturity, better agronomic quality, higher nutritional value, and uniformity in germination times, stand establishment, growth rate, maturity, and fruit size.
Plant breeding techniques take advantage of how a plant is naturally pollinated. There are two general methods of pollination. A plant is self-pollinated when pollen from one flower is transferred to the same flower or another flower of the same plant. A plant is cross-pollinated when pollen comes to it from a flower of a different plant.
Corn plants (Zea mays L.) can be bred by both self-pollination and cross-pollination. Both types of pollination involve the corn plant's flowers. Corn has separate male and female flowers on the same plant, which are located on the tassel and the ear, respectively. Natural pollination occurs in corn when the wind blows pollen from the tassels to the silks that protrude from the tops of the ear shoot.
Plants that have been self-pollinated and selected for type over many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny, i.e., a homozygous plant. A cross between two such homozygous plants produces a uniform population of hybrid plants that are heterozygous for many gene loci and phenotypically uniform.
The development of uniform corn plant hybrids requires developing homozygous inbred plants, crossing these inbred plants, and evaluating these crosses. Pedigree breeding and recurrent selection are examples of breeding methods used to develop hybrid parent plants from breeding populations. Those breeding methods combine the genetic backgrounds from two or more inbred plants or various other broad-based sources into breeding pools from which new inbred plants are developed by selfing combined with phenotypic or genotypic selection. The new inbred plants are crossed with other inbred plants and the hybrids produced by these crosses are evaluated for commercial potential.
North American farmers plant tens of millions of acres of corn at the present time and there are extensive national and international commercial corn breeding programs. A continuing goal of these corn breeding programs is to develop corn hybrids that are based on stable inbred plants and have one or more desirable characteristics. To accomplish this goal, the corn breeder must select and develop superior inbred parental plants.